1989 26 PC - Planed Cruise Speed


4

45426pc

New member
Hi Folks, new to Formula and the forum but have been soaking in a ton of great info. Here's my issue, if anyone is able to lend an opinion, I'd appreciate it!

1989 26 PC 7.4/B1 - WOT is right at 4500RPM, top speed ~35mph GPS and currently 17p 3 blade prop. I'm fine with the top speed, and honestly don't plan to be a speed demon, she's a heavy gal.

My issue is it seems like if I go much under 4k RPM, I start falling off of plane. I'd like to cruise about 3200-3400RPM on plane for a few longer trips I have planned this summer as that seems like a safe RPM at extended times.

I have a failed trim solenoid, so I haven't played with the trim tabs yet. Are trim tabs the answers, or would a prop change help me get a good cruising speed (at the cost of top speed)? I'm newer to a 'bigger boat' as opposed to an open bow, but anything under 3900RPM I feel like I'm just plowing and not very efficient/heavy load on the engine.

Is this just the bigger boat feel, where I'm going to just be plowing at those RPM, or should I feel more on top of the water at ~3300RPM? She feels great at 4k but I just don't want to be revving that high for an hour long trip. If any other 26 PC's are out there and can just give some info on what their cruise speed/RPM is, that would be awesome. Thanks!
 
I don't have a 26PC but with WOT at 4500 and falling off plane at 4000, there seems to be something wrong. I don't think trim tabs are going to help you stay on plane. At the end of the day, they end up adding some drag when extended and on my boat I typically use them to help me level the boat across the beam. What are you doing in terms of outdrive trim? Also, seeing as this is an older boat, its very conceivable that the drive itself was changed at one point in time and someone may not have put the properly geared version on. I would suggest reaching out to Formula TAG (Technical Assistance Group) and getting some info from the on what your boat should have had for both the outdrive gear ratio and what the proper prop size and pitch is. And if you're asking if they will have info for a 34 year old boat, they very likely will and are always eager to help in my experience.
 
That was my thought on the trim tabs, but I've heard other people say they use them for more than just list mitigation. I'm new to cabin cruisers, so still learning a lot. I have the trim tabs repaired, so I'll be able to at least play with it a bit next time I can get in the water.

I had the trim all the way down to try to push the bow down as opposed to bringing it up. I would think raising it would bring the bow up more, and have more of a plowing effect. I also checked the serial on the drive and the engine cover and they match, as well as the prop matching what factory spec was based on what I can find.

What seems odd is that my top speed at WOT is exactly what it should be from factory from all that I've read. I know she's not going to leap out of the water like an open bow, but I would think that it should stay more on top of the water at ~3500RPMs.

I did reach out to Formula a few weeks back on getting a manual, but they said they didn't have anything going that far back. Maybe a different story for other things, I've heard really good things about them.

Thanks for the help!
 
a failed trim solonoid would prevent you from trimming the drives, not the trim tabs. I would get both drives operating correctly before making any changes. If the drives are not trimming up, you will be stuffing the bow into the water.
 
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